Embodiments disclosed herein relate to elevator systems, and more particularly to load bearing members to suspend and/or drive elevator cars of an elevator system.
Elevator systems are useful for carrying passengers, cargo, or both, between various levels in a building. Some elevators are traction based and utilize load bearing members such as ropes or belts for supporting the elevator car and achieving the desired movement and positioning of the elevator car.
Metal ropes for high rise lifting are heavy and large relative to their tensile strength and stiffness. Alternatively, belts are often used as load bearing members. Where a belt is used as a load bearing member, a plurality of tension members, or cords, are embedded in a common jacket. The jacket retains the cords in desired positions and provide a frictional load path. In an exemplary traction elevator system, a machine drives a traction sheave with which the belts interact to drive the elevator car along a hoistway. Belts typically utilize tension members formed from steel elements, but these belts have many of the same issues as steel ropes in high rise lifting applications. Alternatively may utilize tension members formed composites, such as carbon fiber composites.
In a carbon fiber composite tension member, the members have good strength to weight characteristics, but typically have reduced flexibility due to the rigid thermoset matrix utilized, and also reduced high temperature performance compared to tension members formed from steel wires.